Drained the oil... smells like gas?

[81xsproject]

I recently recieved this bike for free. The previous owner said that one of the carbs was flooding and needed to have the floats adjusted. When I drained the oil it smells like gas. Could a flooding carb send gas all the way down into the crank case? If so, what route? also, the air cleaner asmb is off.

[Dragonrider]

Yep. Well known bug on these bikes when the petcocks aren't shutting off (via vacuum) and there is a leaking float valve. Likely the float valves needles need replaced and adjusted.

Gas runs through the intake and past the pistons into the oil. Don't run it like that. The oil is (obviously) thin, and will foam terribly and spew oil out of every possible orafice.

Fix/clean/adjust the carbs, fix the petcocks (or octopus on a special) and off you go!

[81xsproject]

how can I test who in this cenario is at fault

[ratbyk]

Flooding

You have at least 2 problems. A faulty petcock (or two) and a faulty needle/seat/float (or four).
Remove the fuel lines (one at a time) from the petcocks. If fuel flows while in the run or reserve position that petcock needs servicing. Refer to the Tech Tip section.
Remove the carburetors, float bowls and invert (turn over) the bank of carbs. Blow into the fuel lines one at a time. If you can move air (mouth pressure). Into either one, a needle and seat is not doing it's job. Again refer to the Tech Tip section.
It is not rocket science, just common sense.
If the petcocks are functioning properly there will be no fuel flow unless the engine is running. If the N/S/floats are doing their job, fuel flow will stop there until the floats drop and ask for more fuel.
Ken/Sooke
78E Ratbyk
82 FT500 "lilRat"
92 ZX11 Temptress

[TopCatGr58]

Hey Ken,

His profile shows his to be an 81SH, Special, and their petcocks DO flow in RUN or Prime, or Reserve, cause they are supposed to be stopped by the Octopus! If they stop running in Off, then they and their rubber valve gasket are probably still okay, but he'll need to check out the fuel lines below the octopus, to see if fuel flows past it at the carbs when the petcocks are in Run, but the bike is not running! If fuel IS flowing, then the Octopus is suspect, and he will need to either rebuild it, or get rid of it, and turn the fuel off by hand at the petcock when stopped/parked!!

[ratbyk]

Flooding

Good point TC. I am not familiar with Specials owning a Standard. My observations would still apply though. He just has to move a little farther "down stream".
From all of the whining and threads on the octopus I have seen on this Forum if I acquired a Special I think the first thing I would do is scrap it and go with individual fuel lines and separate off/on taps. In line filters as well. 25 year old fuel tanks have a surplus of crap/rust/scale/sh_t floating around.
Ken/Sooke
78E Ratbyk
82 FT500 "lilRat"
92 ZX11 Temptress

[sixtysix]

Originally posted by 81xsproject
how can I test who in this cenario is at fault

Easy, take off the air box and turn on the gas (or prime) and it will come out of the carb that is leaking by.

[ratbyk]

Flooding

Only prob with that suggestion is you still have to pull the carbs to get the air box off. If you already have the carbs off why not do the repairs to them and be done with it. Of course this would be after doing 2 more carb cleanings to achieve the triple clean status.
Ken/Sooke

[nashville_bill]

You really don't have to remove the carbs to pull the air box off of them. Just take the lower part off, remove the three bolts, loosen the four screws in the top, loosen the four screws on the rubber manifolds and pull the air box down. Then you can see the intakes of all four carbs.

But you don't even have to do that. Just remove the lower part of the air box -- the part that holds the filter. Then you can look up into the air box and see which carb is flooding.

[Pat Kelly]

Why not just remove the drain screws (bolts) from the bottom of the float bowls?

[John]

Removing the drain screws will just allow the float to drop as the fuel level in the bowl falls, and it will never stop flowing.

[ratbyk]

Flooding

If after the float bowls drain themselves with the drain plugs out then stop, the vacuum valve in the octopus is OK. If fuel continues to flow then the vacuum valve is no good. If fuel only flows from one or two carbs then the vacuum valve is no good AND the N/S/float on the leaking carb/carbs is/are no good as well.
Gets confusing doesn't it.
Ken/Sooke

[grifff]

...

Was wondering. When i bought my bike it was only firing on 2 cylinders. If plugs aren't firing or firing right wouldn't un burnt gas leak past? My petcocks are fine and i had a little gas smell in my oil when i changed it. Just another possibility besides petcocks? PO had wrong plugs in.